This invention relates to engines and, more particularly, to a gas turbine engine having a variable area exhaust nozzle for controlling flow through a cooling passage associated with the gas turbine engine.
Gas turbine engines are widely known and used for power generation and vehicle (e.g., aircraft) propulsion. A typical gas turbine engine includes a compression section, a combustion section, and a turbine section that utilize a primary airflow into the engine to generate power or propel the vehicle. The gas turbine engine is typically mounted within a housing, such as a nacelle. A bypass airflow
The temperature of the bypass airflow is relatively cool compared to the engine and is used as an engine cooling source. For example, a portion of the bypass airflow is bled at an upstream location into a cooling passage within the engine compartment and used to absorb heat from engine components. The cooling passage discharges the bleed flow at a downstream location back into the bypass airflow. Although effective for cooling, the bleed flow is generally unregulated and penalizes bypass airflow thrust efficiency by imparting pressure loss to the cooling air. New jet engine technology with geared systems, and aircraft with increasing electrical systems (replacing pneumatic systems) require significantly increased cooling requirements. Thus, there is a need for a method and system controlling the bleed flow to increase engine efficiency.